Ashwagandha
Content by: OpenSupplement Editorial Team | Medical review: pending | Last updated: April 13, 2026
TL;DR
Premier Ayurvedic adaptogen that helps the body manage stress
Strongest evidence for lowering cortisol and improving sleep quality
Moderate evidence for cognitive support; low evidence for metabolic/liver health
Unique 'non-sedative' calming effect; builds over several weeks
Generally safe; may stimulate thyroid or cause 'emotional blunting' in some
Cost: ~$12-20/month
Best for: Stress-related sleep issues, cortisol management, burnout recovery
What it is
Ashwagandha (Withania somnifera) is often called 'Winter Cherry' or 'Indian Ginseng.' As an adaptogen, it doesn't push the body in one direction; rather, it helps the system return to equilibrium (homeostasis). The name somnifera literally means 'sleep-inducing' in Latin, reflecting its long history of use for rest.
The primary active compounds are withanolides. Ashwagandha's main claim to fame is its ability to lower serum cortisol—the body's primary stress hormone. By blunting the 'fight or flight' response, it allows the parasympathetic nervous system to take over, which is essential for deep, restorative sleep.
What the research says
Ashwagandha is highly effective for sleep, especially when stress is the root cause. Cortisol Reduction. A study by K. Chandrasekhar et al. (2012)[2] showed that high-concentration full-spectrum ashwagandha root extract reduced serum cortisol by nearly 30%. Sleep Parameters. A 2021 meta-analysis of five RCTs found that ashwagandha significantly improved sleep quality and reduced sleep onset latency in both healthy adults and those with insomnia. Recommendation. It is most effective when taken daily for at least 8 weeks. [1]
Emerging evidence suggests neuroprotective benefits. Executive Function. A study in the Journal of Dietary Supplements showed that ashwagandha improved memory and executive function in people with MCI. Amyloid Clearance. Animal studies suggest withanolides may help clear amyloid-beta plaques, though human trials are in very early stages. It is a promising, though not yet 'proven,' cognitive support tool. [3]
Some data shows ashwagandha may improve insulin sensitivity and lower blood sugar. The Evidence. A small trial found results comparable to oral hypoglycemic drugs, but the sample sizes are too small to make definitive claims. Practicality. It is best viewed as a supporting player that reduces the 'stress-induced' blood sugar spikes rather than a primary metabolic treatment.
There is very little evidence for ashwagandha as a liver supplement. While some animal models show 'hepatoprotective' effects against toxins, human data is essentially non-existent. In fact, there are rare case reports of ashwagandha-induced liver injury at very high doses, though these are extremely uncommon. [4]
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Ashwagandha on Amazon
Safety
Generally safe, but with a few caveats. It can stimulate the thyroid, which is good for subclinical hypothyroidism but bad for hyperthyroidism. Some users report 'anhedonia' (emotional blunting) after long-term use; if this happens, cycling off for 2 weeks usually resolves it.
Interactions
- Thyroid Meds: May increase thyroid hormone levels too much.
- Immunosuppressants: May increase immune activity, counteracting the drugs.
- Diabetes Meds: May cause blood sugar to drop too low (additive effect).
Dosing
Standardized Extract: 300-600 mg of KSM-66 or Sensoril extract daily. Timing: Split doses (morning and night) or a single dose in the evening. Form: Look for KSM-66 for general use or Sensoril if you want a more 'sedating' feel.
Cost
Moderate. Quality extracts typically cost $12-20 per month.
The bottom line
Ashwagandha is the ultimate 'stress buffer.' If your sleep and brain fog are casualties of a high-cortisol lifestyle, this is one of the most effective tools in the supplement cabinet.
References
- Langade D, Kanchi S, Salve J, et al. Efficacy and Safety of Ashwagandha (Withania somnifera) Root Extract in Insomnia and Anxiety: A Double-blind, Randomized, Placebo-controlled Study. Cureus. 2019;11(9):e5797.
- Chandrasekhar K, Kapoor J, Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian J Psychol Med. 2012;34(3):255-262.
- Choudhary D, Bhattacharyya S, Bose S. Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions. J Diet Suppl. 2017;14(6):599-612.
- Björnsson ES, Bergmann OM, Björnsson HK, et al. Incidence, presentation, and outcomes in patients with drug-induced liver injury in the general population of Iceland. Gastroenterology. 2013;144(7):1419-1425.
Sources for this page include published meta-analyses, systematic reviews, and NIH dietary supplement fact sheets. All claims reflect the evidence as of early 2026.
This is not medical advice. Consult your healthcare provider before starting any supplement, especially if you take medications.